#!/bin/env python
def char2num(s):
	return{'0':0,'1':1,'2':2,'3':3,'4':4,'5':5,'6':6,'7':7,'8':8,'9':9}[s]
def str2int(s):
	return reduce(lambda x,y:x*10+y,map(char2num,s))
if __name__=='__main__':
	r=str2int('13579')
	print r
